The present invention relates to machinery having multiple hydraulically actuated functions and, more particularly, to a control system for using a single proportional valve to control multiple hydraulically actuated functions on a piece of machinery such as a tractor or front-end wheel loader.
Construction machinery such as road graders and front-end wheel loaders as well as farm machinery such as farm tractors typically include a plurality of hydraulically actuated features or functions such as a front end loader, grading blade, backhoe assembly, etc. These features may include multiple hydraulically actuated movements. For example, a road grader may include a blade lift, blade tilt, and ripper lift, which all may require separate hydraulic cylinders for operation. In addition, these vehicles, particularly farm tractors may be hydraulically coupled to an implement such as a planter, cultivator, or other farm implement. Some implements may include hydraulic systems that articulate or operate particular features of the implement such as lifting or extending wheels. Generally, an input such as a joystick and/or a plurality of selector switches is mounted in the cab or on a panel of the machinery. The input allows an operator to control the hydraulically actuated functions of the construction machinery or implement.
According to an illustrative embodiment of the present invention, a control system for a construction apparatus includes a hydraulic pump adapted to supply hydraulic fluid to a plurality of hydraulically actuated functions, the control system comprising a proportional valve adapted to selectively control a flow of hydraulic fluid from the hydraulic pump, a plurality of direction valves in communication with the proportional valve and the plurality of hydraulically actuated functions, the directional valves configured to selectively direct hydraulic fluid from the proportional valve to at least one of the hydraulically actuated functions, a first input adapted to actuate the proportional valve to control the flow of hydraulic fluid from the pump to the plurality of directional valves, and a second input adapted to actuate at least one of the plurality of directional valves to supply hydraulic fluid to a corresponding hydraulically actuated function.
According to a further illustrative embodiment of the present invention, a construction apparatus comprises a hydraulic pump adapted to produce pressurized hydraulic fluid, a proportional valve adapted to control a flow rate of hydraulic fluid supplied by the hydraulic pump, a plurality of hydraulically actuated implements, a plurality of inputs, at least one of the inputs corresponding to the proportional valve, at least one of the inputs corresponding to one of the hydraulically actuated implements, and a plurality of directional valves in communication with the proportional valve and the plurality of hydraulically actuated implements, the plurality of directional valves adapted to receive input from the plurality of inputs and direct hydraulic fluid from the proportional valve to the corresponding hydraulically actuated implement.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.